Decoration for a music box



FIG. 1 is a side view of a decoration for a music box showing my new design;

FIG. 2 is a side view of the opposite side thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof; and,

FIG. 5 is a top view thereof. 

The ornamental design of a decoration for a music box, as shown and described. 